Electron sources are known from a plurality of fields. Thereby, for example, electron beams are used for material modification, charging of surfaces, imaging of samples, and the like.
Modern manufacturing processes for capacitors on large area substrates or webs, for manufacturing of large area foils, for manufacturing of thin-film solar cells, and the like have a tendency towards decreasing manufacturing costs by enlarging the substrates or webs. Further, substrate sizes are increased to speed up manufacturing processes. In order to increase the throughput of a manufacturing apparatus, the energy density provided by a source onto a substrate, foil, sheets or web that is required for certain processes should also be increased.
For example, manufacturing of ceramic and electrolyte capacitors on foils by sputtering deposition processes can be applied. During deposition of the materials on the foil, heat is generated that needs to be reduced by contacting the foil to a cooled roller. Thereby, cooling of the foil depends on the contact of the foil to the roller. The contact is often realized by electrostatic forces. Thereby, the surface of the foil can be charged by an electron source. For charging the surface of a foil, for example, electron flood guns can be applied.
The desire to up-size manufacturing apparatuses and to increase the manufacturing speed of foils, sheets, films, electronic components, and the like make it desirable to improve the manufacturing apparatuses.